Re: [PATCH 2/2] tests/9pfs: fix coverity error in create_local_test_dir()

[Greg Kurz]

On Fri, 30 Oct 2020 12:59:48 +0100
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:

> On Freitag, 30. Oktober 2020 12:44:18 CET Greg Kurz wrote:
> > On Fri, 30 Oct 2020 09:19:46 +0100
> > 
> > Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > > Coverity wants the return value of mkdir() to be checked, so let's
> > > pretend to do that. We're actually just making a dummy check and
> > > ignore the result, because we actually only care if the required
> > > directory exists and we have an existence check for that in place
> > > already.
> > 
> > I see that sometimes changelog shows a copy of the original
> > coverity report (e.g. commit df1a312fea58).
> 
> Ok, I'll add that.
> 
> > > Reported-by: Greg Kurz <groug@kaod.org>
> > 
> > Please give credits to coverity, not me :-)
> > 
> > And most importantly, we want to mention the CID in the changelog.
> > 
> > e.g.
> > 
> > Reported-by: Coverity (CID 1435963)
> 
> Ok.
> 
> It's not clear to me where this coverity report is accessible online. A quick 
> search only brought me to statistics about its latest check, but not the 
> details of the report you quoted.
> 

I've been notified by mail because I have an account there.

https://scan.coverity.com/users/sign_up

> And more importantly: is there coverity CI support that one could enable on 
> github, so that pending patches were checked before upstream merge?
> 

I see that Peter already provided the details.

> > 
> > > Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > > ---
> > > 
> > >  tests/qtest/libqos/virtio-9p.c | 6 +++++-
> > >  1 file changed, 5 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/tests/qtest/libqos/virtio-9p.c
> > > b/tests/qtest/libqos/virtio-9p.c index 6b22fa0e9a..0a7c0ee5d8 100644
> > > --- a/tests/qtest/libqos/virtio-9p.c
> > > +++ b/tests/qtest/libqos/virtio-9p.c
> > > @@ -48,9 +48,13 @@ static void init_local_test_path(void)
> > > 
> > >  static void create_local_test_dir(void)
> > >  {
> > >  
> > >      struct stat st;
> > > 
> > > +    int res;
> > > 
> > >      g_assert(local_test_path != NULL);
> > > 
> > > -    mkdir(local_test_path, 0777);
> > > +    res = mkdir(local_test_path, 0777);
> > > +    if (res < 0) {
> > > +        /* ignore error, dummy check to prevent error by coverity */
> > 
> > Why not printing an error message with errno there like you did in
> > the previous patch ?
> 
> Yeah, originally I didn't want to trigger false positives on automated CIs if 
> mkdir() failed just because the directory already exists. But OTOH 

mkdtemp() should buy you the directory doesn't exist.

> g_test_message() is just an info-level message, so it is Ok to bark silently 
> and I will add it.
> 
> > 
> > > +    }
> > > 
> > >      /* ensure test directory exists now ... */
> > >      g_assert(stat(local_test_path, &st) == 0);
> 
> Thanks!
> 
> Best regards,
> Christian Schoenebeck
> 
>